Fix PR7272 in -tailcallelim instead of the inliner

The -tailcallelim pass should be checking if byval or inalloca args can
be captured before marking calls as tail calls.  This was the real root
cause of PR7272.

With a better fix in place, revert the inliner change from r105255.  The
test case it introduced still passes and has been moved to
test/Transforms/Inline/byval-tail-call.ll.

Reviewers: chandlerc

Differential Revision: http://reviews.llvm.org/D3403

llvm-svn: 206789

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp b/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp
index 6d02777d091..2f77f9c404f 100644
--- a/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp
@@ -204,6 +204,15 @@ bool TailCallElim::runOnFunction(Function &F) {
     }
   }
 
+  // If any byval or inalloca args are captured, exit. They are also allocated
+  // in our stack frame.
+  for (Argument &Arg : F.args()) {
+    if (Arg.hasByValOrInAllocaAttr())
+      PointerMayBeCaptured(&Arg, &ACT);
+    if (ACT.Captured)
+      return false;
+  }
+
   // Second pass, change any tail recursive calls to loops.
   //
   // FIXME: The code generator produces really bad code when an 'escaping